Intra Calferol is pH neutral and has excellent vitamin stability. The mixture of calcium salts and chelates has high bioavailability and the phosphorus activator releases more organic phosphorus from its reserves in feed. The micro element magnesium is essential for the bone and eggshell matrix. Vitamin D3, which regulates calcium, phosphorus, and magnesium metabolism, is thus essential for bone formation and good eggshell quality.